package defects.libvirt.unit;

import java.util.*;

/**
 * Unit tests for libvirt-0002: x86ModelFromCPU x86FeatureFind O(C×F).
 */
public class Libvirt0002Test {

    static int passed = 0;
    static int failed = 0;

    static void assertTrue(String label, boolean condition) {
        if (condition) {
            System.out.println("  PASS: " + label);
            passed++;
        } else {
            System.out.println("  FAIL: " + label);
            failed++;
        }
    }

    public static void main(String[] args) {
        System.out.println("libvirt-0002 unit tests");
        System.out.println("=".repeat(50));

        testDefectiveCountsCorrectly();
        testFixedCountsCorrectly();
        testBothResolveToSameIndices();
        testMissingFeatureHandled();
        testOpRatioAbove200xAtF500();
        testEmptyCpuFeatures();

        System.out.println();
        System.out.printf("Result: %d passed, %d failed%n", passed, failed);
        if (failed > 0) System.exit(1);
    }

    static void testDefectiveCountsCorrectly() {
        System.out.println("\n--- testDefectiveCountsCorrectly ---");
        int f = 10, c = 3;
        List<String> mapList = Libvirt0002CpuFeatureFindAlgorithm.buildMapFeatureList(f);
        // CPU features are the last 3: map-feat-7, map-feat-8, map-feat-9
        List<String> cpuFeats = Libvirt0002CpuFeatureFindAlgorithm.buildCpuFeatures(mapList, c);

        Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind def =
            new Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind();
        def.resolveFeatures(cpuFeats, mapList);

        // Each of the 3 CPU features is at position 7,8,9 → 8+9+10=27 comparisons
        assertTrue("Defective comparisons = 27 at F=10, C=3 (worst case): " + def.comparisons,
            def.comparisons == 27);
    }

    static void testFixedCountsCorrectly() {
        System.out.println("\n--- testFixedCountsCorrectly ---");
        int f = 10, c = 3;
        List<String> mapList = Libvirt0002CpuFeatureFindAlgorithm.buildMapFeatureList(f);
        Map<String, Integer> mapIdx = Libvirt0002CpuFeatureFindAlgorithm.buildFeatureIndex(mapList);
        List<String> cpuFeats = Libvirt0002CpuFeatureFindAlgorithm.buildCpuFeatures(mapList, c);

        Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind fix =
            new Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind();
        fix.resolveFeatures(cpuFeats, mapIdx);

        // Fixed: exactly C hash lookups
        assertTrue("Fixed comparisons = C = " + c + ": " + fix.comparisons,
            fix.comparisons == c);
    }

    static void testBothResolveToSameIndices() {
        System.out.println("\n--- testBothResolveToSameIndices ---");
        int f = 50, c = 20;
        List<String> mapList = Libvirt0002CpuFeatureFindAlgorithm.buildMapFeatureList(f);
        Map<String, Integer> mapIdx = Libvirt0002CpuFeatureFindAlgorithm.buildFeatureIndex(mapList);
        List<String> cpuFeats = Libvirt0002CpuFeatureFindAlgorithm.buildCpuFeatures(mapList, c);

        Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind def =
            new Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind();
        List<Integer> defResult = def.resolveFeatures(cpuFeats, mapList);

        Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind fix =
            new Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind();
        List<Integer> fixResult = fix.resolveFeatures(cpuFeats, mapIdx);

        // Sort both for comparison (HashMap ordering may differ from list)
        Collections.sort(defResult);
        Collections.sort(fixResult);
        assertTrue("Both resolve same indices: def=" + defResult + " fix=" + fixResult,
            defResult.equals(fixResult));
        assertTrue("Resolved count = C = " + c, defResult.size() == c);
    }

    static void testMissingFeatureHandled() {
        System.out.println("\n--- testMissingFeatureHandled ---");
        List<String> mapList = List.of("feat-a", "feat-b", "feat-c");
        Map<String, Integer> mapIdx = Map.of("feat-a", 0, "feat-b", 1, "feat-c", 2);
        List<String> cpuFeats = List.of("feat-a", "feat-MISSING", "feat-c");

        Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind def =
            new Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind();
        List<Integer> defResult = def.resolveFeatures(cpuFeats, mapList);

        Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind fix =
            new Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind();
        List<Integer> fixResult = fix.resolveFeatures(cpuFeats, mapIdx);

        assertTrue("Missing feature skipped (defective): size=2, got=" + defResult.size(),
            defResult.size() == 2);
        assertTrue("Missing feature skipped (fixed): size=2, got=" + fixResult.size(),
            fixResult.size() == 2);
        assertTrue("Both return {0,2}", defResult.contains(0) && defResult.contains(2)
            && fixResult.contains(0) && fixResult.contains(2));
    }

    static void testOpRatioAbove200xAtF500() {
        System.out.println("\n--- testOpRatioAbove200x at F=500, C=100 ---");
        int f = 500, c = 100;
        List<String> mapList = Libvirt0002CpuFeatureFindAlgorithm.buildMapFeatureList(f);
        Map<String, Integer> mapIdx = Libvirt0002CpuFeatureFindAlgorithm.buildFeatureIndex(mapList);
        List<String> cpuFeats = Libvirt0002CpuFeatureFindAlgorithm.buildCpuFeatures(mapList, c);

        Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind def =
            new Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind();
        def.resolveFeatures(cpuFeats, mapList);

        Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind fix =
            new Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind();
        fix.resolveFeatures(cpuFeats, mapIdx);

        double ratio = (double) def.comparisons / Math.max(fix.comparisons, 1);
        System.out.printf("  defective=%d, fixed=%d, ratio=%.1f×%n",
            def.comparisons, fix.comparisons, ratio);
        assertTrue("Op-count ratio >= 200× at F=500, C=100: " + ratio, ratio >= 200.0);
    }

    static void testEmptyCpuFeatures() {
        System.out.println("\n--- testEmptyCpuFeatures ---");
        List<String> mapList = Libvirt0002CpuFeatureFindAlgorithm.buildMapFeatureList(10);
        Map<String, Integer> mapIdx = Libvirt0002CpuFeatureFindAlgorithm.buildFeatureIndex(mapList);
        List<String> cpuFeats = Collections.emptyList();

        Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind def =
            new Libvirt0002CpuFeatureFindAlgorithm.DefectiveFeatureFind();
        List<Integer> defResult = def.resolveFeatures(cpuFeats, mapList);
        assertTrue("Empty CPU features → empty result (defective)", defResult.isEmpty());

        Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind fix =
            new Libvirt0002CpuFeatureFindAlgorithm.FixedFeatureFind();
        List<Integer> fixResult = fix.resolveFeatures(cpuFeats, mapIdx);
        assertTrue("Empty CPU features → empty result (fixed)", fixResult.isEmpty());
    }
}